/******************* (C) COPYRIGHT 2022 CHU WEI TENG ***********************************************
**
**------------------ File Info ---------------------------------------------------------------------
** File name:      dwin_list.h
** modified Date:  2022-05-10
** Last Version:   V1.0
** Descriptions: 
** 
**------------------ Modfication  log --------------------------------------------------------------
** Date       Who            Rev        Comments
----------------------------------------------------------------------------------------------------
   22/05/10  chuwt@qq.com    V1.00      created

****************************************************************************************************/

#ifndef __DWIN_LIST_H
#define __DWIN_LIST_H

/* The definitions of this file are adopted from those which can be
   found in the Linux kernel headers to enable people familiar with
   the latter find their way in these sources as well.  */

/* Basic type for the double-link list.  */
typedef struct dwin_list_head
{
  struct dwin_list_head *next;
  struct dwin_list_head *prev;
} dwin_list_t;


/* Define a variable with the head and tail of the list.  */
#define DWIN_LIST_HEAD(name) \
  dwin_list_t name = { &(name), &(name) }

/* Initialize a new list head.  */
#define DWIN_INIT_LIST_HEAD(ptr) \
  (ptr)->next = (ptr)->prev = (ptr)


static __inline void __dwin_list_add(dwin_list_t *n, dwin_list_t *prev, dwin_list_t *next)
{
    next->prev = n;
    n->next = next;
    n->prev = prev;
    prev->next = n;
}

/* Add new element at the head of the list.  */
static __inline void dwin_list_add (dwin_list_t *newp, dwin_list_t *head)
{
  newp->next = head->next;
  newp->prev = head;
  head->next->prev = newp;
  head->next = newp;
}

static __inline void list_add_tail(dwin_list_t *n, dwin_list_t *head)
{
   __dwin_list_add(n, head->prev, head);
}

/* Remove element from list.  */
static __inline void dwin_list_del (dwin_list_t *elem)
{
  elem->next->prev = elem->prev;
  elem->prev->next = elem->next;
}


/* Join two lists.  */
static __inline void dwin_list_splice (dwin_list_t *add, dwin_list_t *head)
{
  /* Do nothing if the list which gets added is empty.  */
  if (add != add->next)
    {
      add->next->prev = head;
      add->prev->next = head->next;
      head->next->prev = add->prev;
      head->next = add->next;
    }
}

static __inline unsigned char dwin_list_empty(const dwin_list_t * node)
{
    return (node->next == node);
}


/* Get typed element from list at a given position.  */
#define dwin_list_entry(ptr, type, member) \
  ((type *) ((char *) (ptr) - (unsigned long) (&((type *) 0)->member)))



/* Iterate forward over the elements of the list.  */
#define dwin_list_for_each(pos, head) \
  for (pos = (head)->next; pos != (head); pos = pos->next)


/* Iterate forward over the elements of the list.  */
#define dwin_list_for_each_prev(pos, head) \
  for (pos = (head)->prev; pos != (head); pos = pos->prev)


/* Iterate backwards over the elements list.  The list elements can be
   removed from the list while doing this.  */
#define dwin_list_for_each_prev_safe(pos, p, head) \
  for (pos = (head)->prev, p = pos->prev; \
       pos != (head); \
       pos = p, p = pos->prev)

#endif  /* lib_list.h */
